Maintaining mobility improvement and short channel control as microelectronic device dimensions continue to scale provides a challenge in device fabrication. In particular, during design and manufacture of metal-oxide-semiconductor (MOS) transistor semiconductor devices, such as those used in complementary metal-oxide-semiconductor (CMOS) devices, it is often desired to increase movement of electrons (carriers) in n-type MOS device (NMOS) channels and to increase movement of holes (carriers) in p-type MOS device (PMOS) channels. Fin-based transistor devices can be used to provide improved short channel control. Typical CMOS transistor devices utilize silicon as the channel material for both hole and electron majority carrier MOS channels. Switching to other channel materials can improve mobility. For example, silicon germanium (SixGe1-x, where x<0.2) fin-based channel structures provide mobility enhancement, which is suitable for use in many applications.
As will be appreciated, the figures are not necessarily drawn to scale or intended to limit the present disclosure to the specific configurations shown. For instance, while some figures generally indicate perfectly straight lines, right angles, and smooth surfaces, an actual implementation of an integrated circuit structure may have less than perfect straight lines, right angles, and some features may have surface topology or otherwise be non-smooth, given real world limitations of the processing equipment and techniques used. To this end, the X-SEM image figures have been provided in conjunction with man-made figures to demonstrate examples of actual real world shapes and features, including trench bottoms having low-ion damage and non-faceted morphology according to an embodiment as well as trench bottoms having ion damaged irregular morphology and faceted morphology.